Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756927AbcK3CPa (ORCPT ); Tue, 29 Nov 2016 21:15:30 -0500 Received: from mail-pf0-f177.google.com ([209.85.192.177]:36320 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756231AbcK3COS (ORCPT ); Tue, 29 Nov 2016 21:14:18 -0500 From: David Matlack To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, jmattson@google.com, rkrcmar@redhat.com, pbonzini@redhat.com, David Matlack Subject: [PATCH v3 1/5] KVM: nVMX: generate non-true VMX MSRs based on true versions Date: Tue, 29 Nov 2016 18:14:06 -0800 Message-Id: <1480472050-58023-2-git-send-email-dmatlack@google.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: <1480472050-58023-1-git-send-email-dmatlack@google.com> References: <1480472050-58023-1-git-send-email-dmatlack@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5843 Lines: 148 The "non-true" VMX capability MSRs can be generated from their "true" counterparts, by OR-ing the default1 bits. The default1 bits are fixed and defined in the SDM. Since we can generate the non-true VMX MSRs from the true versions, there's no need to store both in struct nested_vmx. This also lets userspace avoid having to restore the non-true MSRs. Note this does not preclude emulating MSR_IA32_VMX_BASIC[55]=0. To do so, we simply need to set all the default1 bits in the true MSRs (such that the true MSRs and the generated non-true MSRs are equal). Signed-off-by: David Matlack Suggested-by: Paolo Bonzini --- arch/x86/kvm/vmx.c | 45 +++++++++++++++++++-------------------------- 1 file changed, 19 insertions(+), 26 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5382b82..0beb56a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -446,19 +446,21 @@ struct nested_vmx { u16 vpid02; u16 last_vpid; + /* + * We only store the "true" versions of the VMX capability MSRs. We + * generate the "non-true" versions by setting the must-be-1 bits + * according to the SDM. + */ u32 nested_vmx_procbased_ctls_low; u32 nested_vmx_procbased_ctls_high; - u32 nested_vmx_true_procbased_ctls_low; u32 nested_vmx_secondary_ctls_low; u32 nested_vmx_secondary_ctls_high; u32 nested_vmx_pinbased_ctls_low; u32 nested_vmx_pinbased_ctls_high; u32 nested_vmx_exit_ctls_low; u32 nested_vmx_exit_ctls_high; - u32 nested_vmx_true_exit_ctls_low; u32 nested_vmx_entry_ctls_low; u32 nested_vmx_entry_ctls_high; - u32 nested_vmx_true_entry_ctls_low; u32 nested_vmx_misc_low; u32 nested_vmx_misc_high; u32 nested_vmx_ept_caps; @@ -2712,9 +2714,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) vmx->nested.nested_vmx_exit_ctls_high |= VM_EXIT_CLEAR_BNDCFGS; /* We support free control of debug control saving. */ - vmx->nested.nested_vmx_true_exit_ctls_low = - vmx->nested.nested_vmx_exit_ctls_low & - ~VM_EXIT_SAVE_DEBUG_CONTROLS; + vmx->nested.nested_vmx_exit_ctls_low &= ~VM_EXIT_SAVE_DEBUG_CONTROLS; /* entry controls */ rdmsr(MSR_IA32_VMX_ENTRY_CTLS, @@ -2733,9 +2733,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) vmx->nested.nested_vmx_entry_ctls_high |= VM_ENTRY_LOAD_BNDCFGS; /* We support free control of debug control loading. */ - vmx->nested.nested_vmx_true_entry_ctls_low = - vmx->nested.nested_vmx_entry_ctls_low & - ~VM_ENTRY_LOAD_DEBUG_CONTROLS; + vmx->nested.nested_vmx_entry_ctls_low &= ~VM_ENTRY_LOAD_DEBUG_CONTROLS; /* cpu-based controls */ rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, @@ -2768,8 +2766,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) CPU_BASED_USE_MSR_BITMAPS; /* We support free control of CR3 access interception. */ - vmx->nested.nested_vmx_true_procbased_ctls_low = - vmx->nested.nested_vmx_procbased_ctls_low & + vmx->nested.nested_vmx_procbased_ctls_low &= ~(CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING); /* secondary cpu-based controls */ @@ -2868,36 +2865,32 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) *pdata = vmx_control_msr( vmx->nested.nested_vmx_pinbased_ctls_low, vmx->nested.nested_vmx_pinbased_ctls_high); + if (msr_index == MSR_IA32_VMX_PINBASED_CTLS) + *pdata |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_TRUE_PROCBASED_CTLS: - *pdata = vmx_control_msr( - vmx->nested.nested_vmx_true_procbased_ctls_low, - vmx->nested.nested_vmx_procbased_ctls_high); - break; case MSR_IA32_VMX_PROCBASED_CTLS: *pdata = vmx_control_msr( vmx->nested.nested_vmx_procbased_ctls_low, vmx->nested.nested_vmx_procbased_ctls_high); + if (msr_index == MSR_IA32_VMX_PROCBASED_CTLS) + *pdata |= CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_TRUE_EXIT_CTLS: - *pdata = vmx_control_msr( - vmx->nested.nested_vmx_true_exit_ctls_low, - vmx->nested.nested_vmx_exit_ctls_high); - break; case MSR_IA32_VMX_EXIT_CTLS: *pdata = vmx_control_msr( vmx->nested.nested_vmx_exit_ctls_low, vmx->nested.nested_vmx_exit_ctls_high); + if (msr_index == MSR_IA32_VMX_EXIT_CTLS) + *pdata |= VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_TRUE_ENTRY_CTLS: - *pdata = vmx_control_msr( - vmx->nested.nested_vmx_true_entry_ctls_low, - vmx->nested.nested_vmx_entry_ctls_high); - break; case MSR_IA32_VMX_ENTRY_CTLS: *pdata = vmx_control_msr( vmx->nested.nested_vmx_entry_ctls_low, vmx->nested.nested_vmx_entry_ctls_high); + if (msr_index == MSR_IA32_VMX_ENTRY_CTLS) + *pdata |= VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_MISC: *pdata = vmx_control_msr( @@ -10184,7 +10177,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) } if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control, - vmx->nested.nested_vmx_true_procbased_ctls_low, + vmx->nested.nested_vmx_procbased_ctls_low, vmx->nested.nested_vmx_procbased_ctls_high) || !vmx_control_verify(vmcs12->secondary_vm_exec_control, vmx->nested.nested_vmx_secondary_ctls_low, @@ -10193,10 +10186,10 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmx->nested.nested_vmx_pinbased_ctls_low, vmx->nested.nested_vmx_pinbased_ctls_high) || !vmx_control_verify(vmcs12->vm_exit_controls, - vmx->nested.nested_vmx_true_exit_ctls_low, + vmx->nested.nested_vmx_exit_ctls_low, vmx->nested.nested_vmx_exit_ctls_high) || !vmx_control_verify(vmcs12->vm_entry_controls, - vmx->nested.nested_vmx_true_entry_ctls_low, + vmx->nested.nested_vmx_entry_ctls_low, vmx->nested.nested_vmx_entry_ctls_high)) { nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); -- 2.8.0.rc3.226.g39d4020